Messages in this thread | | | Date | Wed, 27 Jan 2021 22:19:39 +0000 | From | Will Deacon <> | Subject | Re: [PATCH v9 0/4] arm64: ARMv8.5-A: MTE: Add async mode support |
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On Wed, Jan 27, 2021 at 09:00:17PM +0100, Andrey Konovalov wrote: > On Tue, Jan 26, 2021 at 2:46 PM Vincenzo Frascino > <vincenzo.frascino@arm.com> wrote: > > > > This patchset implements the asynchronous mode support for ARMv8.5-A > > Memory Tagging Extension (MTE), which is a debugging feature that allows > > to detect with the help of the architecture the C and C++ programmatic > > memory errors like buffer overflow, use-after-free, use-after-return, etc. > > > > MTE is built on top of the AArch64 v8.0 virtual address tagging TBI > > (Top Byte Ignore) feature and allows a task to set a 4 bit tag on any > > subset of its address space that is multiple of a 16 bytes granule. MTE > > is based on a lock-key mechanism where the lock is the tag associated to > > the physical memory and the key is the tag associated to the virtual > > address. > > When MTE is enabled and tags are set for ranges of address space of a task, > > the PE will compare the tag related to the physical memory with the tag > > related to the virtual address (tag check operation). Access to the memory > > is granted only if the two tags match. In case of mismatch the PE will raise > > an exception. > > > > The exception can be handled synchronously or asynchronously. When the > > asynchronous mode is enabled: > > - Upon fault the PE updates the TFSR_EL1 register. > > - The kernel detects the change during one of the following: > > - Context switching > > - Return to user/EL0 > > - Kernel entry from EL1 > > - Kernel exit to EL1 > > - If the register has been updated by the PE the kernel clears it and > > reports the error. > > > > The series is based on linux-next/akpm. > > > > To simplify the testing a tree with the new patches on top has been made > > available at [1]. > > > > [1] https://git.gitlab.arm.com/linux-arm/linux-vf.git mte/v10.async.akpm > > > > Cc: Andrew Morton <akpm@linux-foundation.org> > > Cc: Catalin Marinas <catalin.marinas@arm.com> > > Cc: Will Deacon <will@kernel.org> > > Cc: Dmitry Vyukov <dvyukov@google.com> > > Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> > > Cc: Alexander Potapenko <glider@google.com> > > Cc: Marco Elver <elver@google.com> > > Cc: Evgenii Stepanov <eugenis@google.com> > > Cc: Branislav Rankov <Branislav.Rankov@arm.com> > > Cc: Andrey Konovalov <andreyknvl@google.com> > > Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com> > > Tested-by: Andrey Konovalov <andreyknvl@google.com> > > > Vincenzo Frascino (4): > > arm64: mte: Add asynchronous mode support > > kasan: Add KASAN mode kernel parameter > > kasan: Add report for async mode > > arm64: mte: Enable async tag check fault > > Andrew, could you pick this up into mm? The whole series will need to > go through mm due to dependencies on the patches that are already > there.
Please can you check that it doesn't conflict with the arm64 for-next/core branch first?
Will
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